also += 1 was just an example, it could be += N, += 15 or whatever, it depends on certain conditions , but I think it would work as well


El 17 de marzo de 2010 16:44, Juan Manuel García del Moral <juanmanuel@taringa.net> escribió:
That's exactly what I need, Do you have an idea how can I implement this through the C++ API?

Many thanks


2010/3/17 Ted Zlatanov <tzz@lifelogs.com>
On Wed, 17 Mar 2010 16:29:27 -0300 Juan Manuel García del Moral <juanmanuel@taringa.net> wrote:


JMGdM> I have this:
JMGdM> SocialAds.Anonimos['145']['Tag']['12'] = 13

JMGdM> I would need to to

JMGdM> SocialAds.Anonimos['145']['Tag']['12'] += 1

JMGdM> for example

JMGdM> with that, would be enough for now....

JMGdM> I don't want to retrieve the value, do 13+1 in my code, and re-set() it to
JMGdM> 14

There are several ways, here's one idea:

So your (column family + row) key is A, the SuperColumn is B, and the
Column name is C.  You want to do ${A B C}++

If you can assign an identity to your writers, you can make unique
SuperColumns for each one and each writer can increment its own:

${A B1 C}++
${A B2 C}++
etc.

and then you can gather all the values, for example with bitmask queries
that match B*.  This is a fast operation if you don't have too many
SuperColumns (too many writers).  Do you expect more than 1000?

If you need to ensure that old writers are not counted, also add a
'last' Column:

${A B1 last}=timestamp1

and then your gather process can exclude outdated records.

Ted